// Copyright Fedor Indutny and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

#ifndef SRC_DEBUG_AGENT_H_
#define SRC_DEBUG_AGENT_H_

#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS

#include "node_mutex.h"
#include "util.h"
#include "util-inl.h"
#include "uv.h"
#include "v8.h"
#include "v8-debug.h"

#include <string.h>
#include <string>

// Forward declaration to break recursive dependency chain with src/env.h.
namespace node {
class Environment;
} // namespace node

namespace node {
namespace debugger {

    class AgentMessage {
    public:
        AgentMessage(uint16_t* val, int length)
            : length_(length)
        {
            if (val == nullptr) {
                data_ = val;
            } else {
                data_ = new uint16_t[length];
                memcpy(data_, val, length * sizeof(*data_));
            }
        }

        ~AgentMessage()
        {
            delete[] data_;
            data_ = nullptr;
        }

        inline const uint16_t* data() const { return data_; }
        inline int length() const { return length_; }

        ListNode<AgentMessage> member;

    private:
        uint16_t* data_;
        int length_;
    };

    class Agent {
    public:
        explicit Agent(node::Environment* env);
        ~Agent();

        typedef void (*DispatchHandler)(node::Environment* env);

        // Start the debugger agent thread
        bool Start(const std::string& host, int port, bool wait);
        // Listen for debug events
        void Enable();
        // Stop the debugger agent
        void Stop();

        inline void set_dispatch_handler(DispatchHandler handler)
        {
            dispatch_handler_ = handler;
        }

        inline node::Environment* parent_env() const { return parent_env_; }
        inline node::Environment* child_env() const { return child_env_; }

    protected:
        void InitAdaptor(Environment* env);

        // Worker body
        void WorkerRun();

        static void ThreadCb(Agent* agent);
        static void ParentSignalCb(uv_async_t* signal);
        static void ChildSignalCb(uv_async_t* signal);
        static void MessageHandler(const v8::Debug::Message& message);

        // V8 API
        static Agent* Unwrap(const v8::FunctionCallbackInfo<v8::Value>& args);
        static void NotifyListen(const v8::FunctionCallbackInfo<v8::Value>& args);
        static void NotifyWait(const v8::FunctionCallbackInfo<v8::Value>& args);
        static void SendCommand(const v8::FunctionCallbackInfo<v8::Value>& args);

        void EnqueueMessage(AgentMessage* message);

        enum State {
            kNone,
            kRunning
        };

        State state_;

        std::string host_;
        int port_;
        bool wait_;

        uv_sem_t start_sem_;
        node::Mutex message_mutex_;
        uv_async_t child_signal_;

        uv_thread_t thread_;
        node::Environment* parent_env_;
        node::Environment* child_env_;
        uv_loop_t child_loop_;
        v8::Persistent<v8::Object> api_;

        ListHead<AgentMessage, &AgentMessage::member> messages_;

        DispatchHandler dispatch_handler_;
    };

} // namespace debugger
} // namespace node

#endif // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS

#endif // SRC_DEBUG_AGENT_H_
